feat(browse): Wave-0 Batch C — CapturingAddressSpaceBuilder + CapturedTreeBrowseSession

Task 6: CapturedTree/CapturedNode model + CapturingAddressSpaceBuilder — an in-memory
        IAddressSpaceBuilder that records a driver's DiscoverAsync stream (folder nesting,
        leaf FullName as node id, alarm mark, node-cap truncation, no-op alarm sink).
Task 7: CapturedTreeBrowseSession — serves the captured snapshot through IBrowseSession
        (Root/Expand/Attributes from memory, truncation marker, shared-immutable-tree dispose).
13 unit tests green.

src/Core/ZB.MOM.WW.OtOpcUa.Commons/Browsing/CapturedTree.cs

@@ -0,0 +1,49 @@
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+
+namespace ZB.MOM.WW.OtOpcUa.Commons.Browsing;
+
+/// <summary>One node captured from a driver's DiscoverAsync stream. Folder ids are
+/// path-composed ("/parent/child"); leaf ids are the driver FullName (the commit value).</summary>
+public sealed class CapturedNode
+{
+    /// <summary>Stable identifier. Folder = path-composed ("/parent/child"); leaf = driver FullName.</summary>
+    public required string Id { get; init; }
+
+    /// <summary>Browse name (the path segment under the parent).</summary>
+    public required string Name { get; init; }
+
+    /// <summary>Human-readable display name.</summary>
+    public required string DisplayName { get; init; }
+
+    /// <summary>True for a variable (terminal); false for a folder.</summary>
+    public required bool IsLeaf { get; init; }
+
+    /// <summary>Driver-side attribute metadata; set only on leaves.</summary>
+    public DriverAttributeInfo? Attribute { get; init; }
+
+    /// <summary>True when the driver marked this leaf as an alarm condition during discovery.</summary>
+    public bool IsAlarmMarked { get; set; }
+
+    /// <summary>Captured child nodes (folders first-or-interleaved in stream order).</summary>
+    public List<CapturedNode> Children { get; } = [];
+
+    /// <summary>Captured static properties attached to this node via AddProperty.</summary>
+    public List<(string Name, DriverDataType Type, object? Value)> Properties { get; } = [];
+}
+
+/// <summary>Immutable-after-Build snapshot of a whole discovery capture. May be shared by
+/// multiple coalesced browse sessions — sessions drop their reference on dispose, never mutate.</summary>
+public sealed class CapturedTree
+{
+    /// <summary>Synthetic root; its Children are the top-level captured nodes.</summary>
+    public required CapturedNode Root { get; init; }
+
+    /// <summary>True when the node cap was hit and recording stopped short.</summary>
+    public required bool Truncated { get; init; }
+
+    /// <summary>Number of nodes actually recorded (bounded by the node cap).</summary>
+    public required int Count { get; init; }
+
+    /// <summary>Flat lookup from node id to node (for O(1) Expand/Attributes serving).</summary>
+    public required IReadOnlyDictionary<string, CapturedNode> ById { get; init; }
+}